Swash plate type compressor for automobile air-conditioning

ABSTRACT

An improved swash plate type compressor for automobile airconditioning, includes a swash plate chamber positioned centrally between axially spaced front and rear cylinder halves and having intermediate gas passageways forming a part of with the cylinder block gas passageways which inter-communicate between the suction chambers and the gas storage-discharging chambers of the cylinder halves. Further, the swash plate chamber forms an oil reservoir portion aligned and communicating with the oil reservoir portions of the cylinder halves and constituting a part of oil reservoir for the compressor.

United States Patent 1 Komiya [54] SWASH PLATE TYPE COMPRESSOR FORAUTOMOBILE AIR- CONDITIONING [76] Inventor: Sampei Komiya, No. 1745-1Ohaza Shimokoizumi Ohizumi-cho, Ohragun, Gunma, Japan 221 Filed:Apr.1,l971

21 Appl.N0.: 130,216

[30] Foreign Application Priority Data Apr. 13, 1970 Japan ..45/34730[52] U.S. Cl ..417/269, 91/502 [51] Int. Cl. ..F04b 1/12, F04b 27/08[58] Field of Search .Q ..417/269, 270, 534;

[ 56] References Cited UNITED STATES PATENTS 3,352,485 11/1967 Niki etal. 4l7/269 X Ransom et a1 ..41 7/269 [451 May 1, 1973 10/1945 Ford.....4l7/269 6/1917 Allison ..91/502 FOREIGN PATENTS OR APPLICATlONS610,428 10/1948 Great Britain ..4l7/269 Primary Examiner-Charles .1.Myhre Assistant ExaminerFrank H. McKenzie, Jr. AztomeyToren & McGeady[57] I ABSTRACT An improved swash plate type compressor for automobileair-conditioning, includes a swash plate chamber positioned centrallybetween axially spaced front and rear cylinder halves and havingintermediate gas passageways forming a part of with the cylinder blockgas passageways which intercommunicate between the suction chambers andthe gas storagedischarging chambers of the cylinder halves. Further, theswash plate chamber forms an oil reservoir portion aligned andcommunicating with the oil reservoir portions of the cylinder halves andconstituting a part of oil reservoir for the compressor.

3 Claims, 4 Drawing Figures PATENTEU m 1 273 INVENTOR sAnPE! KomvA BYTamwmdfl ATTORNEY BACKGROUND OF THE INVENTION 1. Field of the InventionThe present invention is concerned with a swash plate type compressor,and more particularly, it relates to an improvement in swash plate typecompressors for use in automobile air-conditioning, which is free of thedrawbacks of the swash plate type compressors of the prior art.

2. Description of the Prior Art The structure and the attendantdrawbacks of the conventional swash plate type compressor will bediscussed hereunder by referring to FIG. I of the accompanying drawingswhich will be explained later. In a swash plate type compressor ingeneral, the swash plate is usually positioned centrally between theopposing cylinders. Accordingly, the cylinder block structure is dividedinto front and rear, or upper and lower, or right and left halves. Inthe swash plate type compressor shown inFIG. 1, the shaft assembly unitA (see FIG. 3) which comprises a swash plate 2 secured to the drivingshaft l and thrust bearings 3 attached to the opposing side faces of theswash plate 2 is positioned in the center of the cylinder block, or inthe other words, between the front cylinder half 4a and the rearcylinder half 4b. A compressing chamber is formed on each side of adouble-headed piston 5 in the front cylinder half 4a and the rearcylinder half 4b, respectively. Axial thrust which is applied to thedriving shaft 1 is absorbed by the thrust bearings 3, whereas radialthrust is absorbed by the radial bearings 6. Symbol B represents an oilreservoir. In a conventional swash plate type compressor having theaforesaid structure, it is necessary that the sum C of the axial lengthsof the swash plate 2 and of the thrust bearings 3 (see FIG. 3) be inexact agreement with the axial distance D of the interval correspondingto said sum C between the front cylinder half 4a and the rear cylinderhalf 4b (see FIGS. 1 and 4); However, it is quite difficult from theaspect of processing these two groups of structural elements to attainthe aforesaid exact agreement between C and D. Therefore, it has beenthe usual practice to compensate for the manufacturing error by the useof a thrust washer or a shim of an appropriate thickness. In the event,however, that this gap regulation or error adjustment is not effectedproperly, there will arise the following hazards. That is to say, incase the adjusted gap is too wide, there will develop knocking sound ornoise. Conversely, if the gap is reduced excessively to an overtightcondition between C and D, then the thrust bearings will be subjected toan overload, causing damage to occur in the bearings. Therefore, themeasurement of the axial distance D between the cylinder halves 4a and4b has required a number of laborious steps. The aforesaid difficulty inprocessing the elements plus the need of a number of additionaltroublesome steps for the adjustment of the distance constitute thefirst drawback of the conventional swash plate type compressor.

Of late, aluminum alloys have come to be used as the materials of thecylinder halves 4a and 4b. In view of the fact, however, that materialof the swash plate 2 as well as the thrust bearings 3 has a thermalexpansion coefficient which is different from that of the material withwhich the cylinder halves 4a and 4b are made, it should be noted thatthe gap between C and D tends to be tightened during the period of alower temperature, whereas it will tend to be broadened during theperiod of a higher temperature, making the adjustment of the gap almostimpossible and impracticable. This difficulty in the adjustment of thegap between C and D due to the difference in the thermal expansioncoefficient of 0 materials represents the second drawback of the swashplate type compressor of the prior art.

SUMMARY OF THE INVENTION It is, therefore, an object of the presentinvention to eliminate the aforesaid drawbacks of the swash plate typecompressors of the prior art and to provide an improved swash plate typecompressor having a novel structure for use in the air-conditioning ofautomobiles.

Another object of the present invention is to provide an improved swashplate type compressor for the purpose described, which needs no thrustwasher or shim for the adjustment of the axial distance between thecylinder halves and the sum of the axial lengths of the swash plate andits thrust bearings.

Still another object of the present invention is to provide an improvedswash plate type compressor for the purpose described, which does notdevelop any harmful difference in thermal expansion coefficient betweenthe material of the swash plate and its thrust bearings and the materialof the cylinder halves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectionalview of a conventional swash plate type compressor.

FIG. 2 is a longitudinal sectional view of the swash plate typecompressor embodying the present invention.

FIG. 3 is a sectional view ofa shaft assembly unit employed in thecompressor of the type described.

FIG. 4 is a vertical sectional view of the swash plate chamber accordingto the present invention.

It should be understood that like elements and parts are indicated bylike reference numerals and symbols throughout the drawings for the sakeof simplicity.

DESCRIPTION OF THE PREFERRED EMBODIMENT As has been stated, it is theobject of the present invention to eliminate the drawbacks encounteredin the swash plate type compressors of the prior art and to provide animproved swash plate type compressor having no such drawbacks. To thisend, the structure of the improved swash plate type compressor of thepresent invention and the attendant advantages thereof will be describedhereunder by way of example by referring to FIGS. 2 through 4.

Referring now to FIG. 2, there is shown a swash plate type compressoraccording to the present invention. This compressor comprises a frontcylinder half 4a and a rear cylinder half 4b, and a swash plate chamber7 which is positioned centrally between these two cylinder halves 4a and4b that is, the compressor comprises theserially arranged parts 4a, 7and 4b. The front cylinder 4a has a cylinder head 8a, and the rearcylinder 4b is of a cylinder head 8b, respectively. The

cylinder head 8a has a gas storage and discharging chamber 9a and a gassucking chamber 10a which are both formed therein, whereas the cylinderhead 8b has a similar gas storage and discharging chamber 9b and a gassucking chamber 10b. These gas storage and discharging chambers 9a and9b communicate with each other, and the gas sucking chambers 10a and 10bcommunicate with each other, by their gas passageways, respectively. Inthe drawing, however, there is shown only one gas passageway 11, for thesake of simplicity, which establishes communication between the gasstorage and discharging chamber 90 and the other gas storage anddischarging chamber 9b. The aforesaid swash plate chamber 7 which is thefeature of the present invention comprises intermediate gas passagewayswhich are aligned in register with the said gas passageways,respectively. In the drawing, however, there is shown only oneintermediate gas passageway at 11a, for the sake of simplicity, which isaligned in register with the said gas passageway 11. The swash platechamber 7 further comprises an intermediate oil reservoir portion Bawhich is aligned in register with the respective portions of the oilreservoir B of both the front and the rear cylinder halves 4a and 4b andwhich also constitutes a part of the said oil reservoir B, and alsocomprises an outletjoint 12 for supplying the compressed gas to anexternal apparatus not shown. It should be understood that this outletjoint 12 may be provided at an appropriate site of some other element ifso desired, for example at an appropriate site of the cylinder block. Itshould be understood, however, that the outlet joint 12 preferably islocated advantageously at such a site, if possible, as having an equaldistance from both of the gas storage and discharging chambers 9a and9b. The contact faces 13a and 13b of the front and the rear cylinderhalves 4a and 4 b which contact, in aligned abutment relation, the saidswash plate chamber 7 are faces which have been finished into planesperpendicular to the longitudinal axis, i.e. the rotation axis 1, of theswash plate type compressor. In the same way, the opposite faces 14a and14b of the swash plate chamber 7 which are placed in alignedface-to-face relation with the faces 13a and 13b of the cylinder halves4a and 4b, respectively, are faces which have been finished intoparallel planes in such a manner that the axial interval or distance Dbetween these two faces 14a and 14b is in exact agreement with the sum Cof the axial lengths of both the swash plate 2 and the thrust bearings3. Besides, the swash plate chamber 7 is made with a metal having athermal expansion coefficient which is identical or substantiallyidentical with that of the material with which the swash plate 2 and thethrust bearings 3 are made.

As has been stated, the swash plate type compressor for automobileair-conditioning according to the present invention features the swashplate chamber 7 having the aforesaid structure which is positionedcentrally between the front cylinder half 4a and the rear cylinder half412. Accordingly, it is quite easy from the aspect of processing theelements to obtain exact agreement of the axial distance D between thefront and the rear cylinder halves 4a and 4b with the sum C of the axiallengths of both the swash plate 2 and the thrust bearings 3, and thusthere is no need for the use of such a member as a thrust washer or ashim for the ad ustment of gaps between- C and D which was required inthe prior art. In other words, the compressor embodying the presentinvention is completely free of the aforesaid first drawback of theconventional swash plate type compressor. Furthermore, in view of thefact that the swash plate chamber 7 is made of a material having athermal expansion coefficient which is identical or substantiallyidentical with that of the material with which the swash plate 2 and thethrust bearings 3 are made, the compressor according to the presentinvention is also free of the aforesaid second drawback of the swashplate type compressor of the prior art.

What is claimed is:

1. A swash plate type compressor for automobile airconditioning,comprising a cylinder block structure including a front cylinder halfand a rear cylinder half disposed in axially aligned and spacedrelationship, and a swash plate chamber member in axial alignment withand extending between said front and rear cylinder halves, said frontcylinder half includes a front cylinder head having a gas storage anddischarging chamber and a gas sucking chamber, said rear cylinder halfincludes a rear cylinder head having a gas storage and dischargingchamber and a gas sucking chamber, said front cylinder half, said swashplate chamber member and said rear cylinder half in combination form afirst gas passageway extending between the gas storage and dischargechambers in said front and rear cylinder heads and a second gaspassageway extending between the gas sucking chambers in said front andrear cylinder heads, said cylinder block structure forming an oilreservoir consisting of first, second and third portions, the firstportion of said oil reservoir formed in said front cylinder half, thethird portion of said oil reservoir formed in said rear cylinder halfand the second portion of said oil reservoir formed in said swash platechamber member and the second portion being in direct communication withthe first and third portions, a driving shaft extending axially throughsaid front and rear cylinder halves and said swash plate chamber member,a swash plate positioned on said driving shaft within said swash platechamber member, and a pair of thrust bearings each mounted on saiddriving shaft and attached to the opposite transverse faces of saidswash plate within said swash plate chamber member, and the axial lengthof said thrust bearings and said swash plate being equal to the axiallength of saidswash plate chamber member.

2. A swash plate type compressor, according to claim 1, wherein thefaces of said front and rear cylinder halves in contact with the endsurfaces of said swash plate member are in planes extendingperpendicularly to the axis of said cylinder block structure, and theopposite faces of said swash plate chamber are in parallel planes.

3. A swash plate type compressor according to claim 1, in which saidswash plate chamber is made with a material having a thermal expansioncoefficient identical or substantially identical with that of thematerial with which the swash plate and the thrust bearings forsupporting this swash plate are made.

1. A swash plate type compressor for automobile airconditioning,comprising a cylinder block structure including a front cylinder halfand a rear cylinder half disposed in axially aligned and spacedrelationship, and a swash plate chamber member in axial alignment withand extending between said front and rear cylinder halves, said frontcylinder half includes a front cylinder head having a gas storage anddischarging chamber and a gas sucking chamber, said rear cylinder halfincludes a rear cylinder head having a gas storage and dischargingchamber and a gas sucking chamber, said front cylinder half, said swashplate chamber member and said rear cylinder half in combination form afirst gas passageway extending between the gas storage and dischargechambers in said front and rear cylinder heads and a second gaspassageway extending between the gas sucking chambers in said front andrear cylinder heads, said cylinder block structure forming an oilreservoir consisting of first, second and third portions, the firstportion of said oil reservoir formed in said front cylinder half, thethird portion of said oil reservoir formed in said rear cylinder halfand the second portion of said oil reservoir formed in said swash platechamber member and the second portion being in direct communication withthe first and third portions, a driving shaft extending axially throughsaid front and rear cylinder halves and said swash plate chamber member,a swash plate positioned on said driving shaft within said swash platechamber member, and a pair of thrust bearings each mounted on saiddriving shaft and attached to the opposite transverse faces of saidswash plate within said swash plate chamber member, and the axial lengthof said thrust bearings and said swash plate being equal to the axiallength of said swash plate chamber member.
 2. A swash plate typecompressor, according to claim 1, wherein the faces of said front andrear cylinder halves in contact with the end surfaces of said swashplate member are in planes extending perpendicularly to the axis of saidcylinder block structure, and the opposite faces of said swash platechamber are in parallel planes.
 3. A swash plate type compressoraccording to claim 1, in which said swash plate chamber is made with amaterial having a thermal expansion coefficient identical orsubstantially identical with that of the material with which the swashplate and the thrust bearings for supporting this swash plate are made.